Article | REF: BM2582 V1

Automotive transmissions - Role and determination of gear ratios

Authors: Elian BARON, Philippe PESCAROU

Publication date: July 10, 2011, Review date: June 29, 2023

You do not have access to this resource.
Click here to request your free trial access!

Already subscribed? Log in!


Français

2. Resistance to vehicle travel

As we have seen, the automotive transmission adapts the power delivered by the engine to the power required at the wheel, by reducing torque and engine speed. The power required at the wheel is a function of the force resisting the vehicle's forward motion, itself the sum of various components which are detailed in this paragraph.

2.1 Aerodynamic resistance

Bernouilli's law states that the resistance exerted by the air on a moving body is proportional to the air's density, the body's frontal area and the square of its forward speed. We also need to take into account the fact that the force required by the body to move through the air depends on its ability to "push aside" the threads of air in its path. This ability to penetrate the air is reflected in a coefficient...

You do not have access to this resource.

Exclusive to subscribers. 97% yet to be discovered!

You do not have access to this resource.
Click here to request your free trial access!

Already subscribed? Log in!


The Ultimate Scientific and Technical Reference

A Comprehensive Knowledge Base, with over 1,200 authors and 100 scientific advisors
+ More than 10,000 articles and 1,000 how-to sheets, over 800 new or updated articles every year
From design to prototyping, right through to industrialization, the reference for securing the development of your industrial projects

This article is included in

Hydraulic, aerodynamic and thermal machines

This offer includes:

Knowledge Base

Updated and enriched with articles validated by our scientific committees

Services

A set of exclusive tools to complement the resources

Practical Path

Operational and didactic, to guarantee the acquisition of transversal skills

Doc & Quiz

Interactive articles with quizzes, for constructive reading

Subscribe now!

Ongoing reading
Resistance to vehicle travel